diff options
| -rw-r--r-- | drivers/scsi/device_handler/scsi_dh.c | 129 |
1 files changed, 105 insertions, 24 deletions
diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c index a9159681ff2..a518f2eff19 100644 --- a/drivers/scsi/device_handler/scsi_dh.c +++ b/drivers/scsi/device_handler/scsi_dh.c @@ -24,8 +24,16 @@ #include <scsi/scsi_dh.h> #include "../scsi_priv.h" +struct scsi_dh_devinfo_list { + struct list_head node; + char vendor[9]; + char model[17]; + struct scsi_device_handler *handler; +}; + static DEFINE_SPINLOCK(list_lock); static LIST_HEAD(scsi_dh_list); +static LIST_HEAD(scsi_dh_dev_list); static struct scsi_device_handler *get_device_handler(const char *name) { @@ -42,21 +50,94 @@ static struct scsi_device_handler *get_device_handler(const char *name) return found; } -static int device_handler_match(struct scsi_device_handler *tmp, - struct scsi_device *sdev) + +static struct scsi_device_handler * +scsi_dh_cache_lookup(struct scsi_device *sdev) { - int i; - - for(i = 0; tmp->devlist[i].vendor; i++) { - if (!strncmp(sdev->vendor, tmp->devlist[i].vendor, - strlen(tmp->devlist[i].vendor)) && - !strncmp(sdev->model, tmp->devlist[i].model, - strlen(tmp->devlist[i].model))) { - return 1; + struct scsi_dh_devinfo_list *tmp; + struct scsi_device_handler *found_dh = NULL; + + spin_lock(&list_lock); + list_for_each_entry(tmp, &scsi_dh_dev_list, node) { + if (!strncmp(sdev->vendor, tmp->vendor, strlen(tmp->vendor)) && + !strncmp(sdev->model, tmp->model, strlen(tmp->model))) { + found_dh = tmp->handler; + break; } } + spin_unlock(&list_lock); - return 0; + return found_dh; +} + +static int scsi_dh_handler_lookup(struct scsi_device_handler *scsi_dh, + struct scsi_device *sdev) +{ + int i, found = 0; + + for(i = 0; scsi_dh->devlist[i].vendor; i++) { + if (!strncmp(sdev->vendor, scsi_dh->devlist[i].vendor, + strlen(scsi_dh->devlist[i].vendor)) && + !strncmp(sdev->model, scsi_dh->devlist[i].model, + strlen(scsi_dh->devlist[i].model))) { + found = 1; + break; + } + } + return found; +} + +/* + * device_handler_match - Attach a device handler to a device + * @scsi_dh - The device handler to match against or NULL + * @sdev - SCSI device to be tested against @scsi_dh + * + * Tests @sdev against the device handler @scsi_dh or against + * all registered device_handler if @scsi_dh == NULL. + * Returns the found device handler or NULL if not found. + */ +static struct scsi_device_handler * +device_handler_match(struct scsi_device_handler *scsi_dh, + struct scsi_device *sdev) +{ + struct scsi_device_handler *found_dh = NULL; + struct scsi_dh_devinfo_list *tmp; + + found_dh = scsi_dh_cache_lookup(sdev); + if (found_dh) + return found_dh; + + if (scsi_dh) { + if (scsi_dh_handler_lookup(scsi_dh, sdev)) + found_dh = scsi_dh; + } else { + struct scsi_device_handler *tmp_dh; + + spin_lock(&list_lock); + list_for_each_entry(tmp_dh, &scsi_dh_list, list) { + if (scsi_dh_handler_lookup(tmp_dh, sdev)) + found_dh = tmp_dh; + } + spin_unlock(&list_lock); + } + + if (found_dh) { /* If device is found, add it to the cache */ + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL); + if (tmp) { + strncpy(tmp->vendor, sdev->vendor, 8); + strncpy(tmp->model, sdev->model, 16); + tmp->vendor[8] = '\0'; + tmp->model[16] = '\0'; + tmp->handler = found_dh; + spin_lock(&list_lock); + list_add(&tmp->node, &scsi_dh_dev_list); + spin_unlock(&list_lock); + } else { + found_dh = NULL; + } + } + + return found_dh; } /* @@ -203,26 +284,18 @@ static int scsi_dh_notifier(struct notifier_block *nb, struct device *dev = data; struct scsi_device *sdev; int err = 0; - struct scsi_device_handler *tmp, *devinfo = NULL; + struct scsi_device_handler *devinfo = NULL; if (!scsi_is_sdev_device(dev)) return 0; sdev = to_scsi_device(dev); - spin_lock(&list_lock); - list_for_each_entry(tmp, &scsi_dh_list, list) { - if (device_handler_match(tmp, sdev)) { - devinfo = tmp; - break; - } - } - spin_unlock(&list_lock); - - if (!devinfo) - goto out; - if (action == BUS_NOTIFY_ADD_DEVICE) { + devinfo = device_handler_match(NULL, sdev); + if (!devinfo) + goto out; + err = scsi_dh_handler_attach(sdev, devinfo); if (!err) err = device_create_file(dev, &scsi_dh_state_attr); @@ -312,6 +385,8 @@ EXPORT_SYMBOL_GPL(scsi_register_device_handler); */ int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) { + struct scsi_dh_devinfo_list *tmp, *pos; + if (!get_device_handler(scsi_dh->name)) return -ENODEV; @@ -320,6 +395,12 @@ int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) spin_lock(&list_lock); list_del(&scsi_dh->list); + list_for_each_entry_safe(pos, tmp, &scsi_dh_dev_list, node) { + if (pos->handler == scsi_dh) { + list_del(&pos->node); + kfree(pos); + } + } spin_unlock(&list_lock); printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); |